The Global Anatomic Staging System Does Not Predict Limb Based Patency of Tibial Endovascular Interventions

Prospective Multi-Center Longitudinal Study to Validate Accuracy of the Global Anatomic Staging System (GLASS) Score in Predicting Major Acute Limb Events in Patients With Chronic Limb Threatening Ischemia Undergoing Endovascular Intervention: The PROMOTE-GLASS Study Protocol

INTRODUCTION

Developed by the Global Vascular Guidelines committee, the Global Limb Anatomic Staging System (GLASS) is an angiographic scoring system used for quantifying infrainguinal disease extent and predicting treatment success with endovascular techniques (EVT). Currently, no other risk prediction model is available for patients with chronic limb threatening ischemia (CLTI) undergoing EVT. GLASS' validation and adoption outside academic institutions for research are limited. Thus, this longitudinal multicenter prospective study aims to examine GLASS' validity and reliability in predicting major acute limb events and overall survival (OS) in patients with CLTI undergoing EVT.

METHODS AND ANALYSIS

This prospective, international, multicenter, observational study will include patients with CLTI undergoing EVT (PROMOTE-GLASS) (ClinicalTrials.gov; ID: NCT06186544) identified through routine clinical referrals and emergency visits to vascular units in participating centers. Only patients who are referred for EVT will be recruited. The primary outcomes are immediate technical success, immediate technical failure, and 1-year limb base patency. The secondary outcomes are major adverse limb events, major lower limb amputation, and OS in patients presenting with CLTI who undergo EVT up to 1 year after the procedure. Clinical and imaging data will be analyzed at the end of follow-up to validate risk prediction. This protocol outlines our approach for identifying cases, GLASS score calculation, outcome measures assessment, and a statistical analysis plan.

ANTICIPATED IMPLICATIONS

PROMOTE-GLASS holds significant implications and can potentially revolutionize clinical decision-making by assisting clinicians in identifying patients who are likely to benefit from EVT. Ultimately, reduce the need for more invasive procedures and improve patient outcomes. Furthermore, PROMOTE-GLASS can provide useful information, including patient selection, for future randomized controlled trials (RCTs) investigating EVT for CLTI. PROMOTE-GLASS anticipated implications on the vascular community are rooted in its potential to improve patient care, inform future research, and address limitations in existing literature regarding CLTI treatment outcomes.

National trends and outcomes of pedal bypass surgery

OBJECTIVE

The technical demands associated with pedal bypass (PB) surgery place it at risk of underutilization and may be limiting its widespread adoption as a valuable revascularization modality. This study aims to evaluate trends in PB performance, assess its outcomes, and compare its results between high- and low-volume centers.

METHODS

All patients receiving a PB between 2003 and 2023 were identified in the Vascular Quality Initiative (VQI) infrainguinal bypass (IIB) module. The ratio of PB to total IIB performed was calculated for each year and trended over the study period. Centers performing PB were categorized according to their annual PB volume into tertiles of low-volume centers (LVC, <2 PB/year), medium-volume centers (MVC, 2-4 PB/year), and high-volume centers (HVC, >4 PB/year) for comparison. Patient characteristics and outcomes were compared using the χ2 or Fisher exact test as appropriate for categorical variables and the analysis of variance test or Kruskal-Wallis test as appropriate for continuous variables. Cox regression analysis was used to study the association between center volume and the primary outcomes of primary patency, primary-assisted patency, secondary patency, reintervention, amputation, and major adverse limb events (MALE), defined as the composite outcome of amputation and/or reintervention.

RESULTS

A total of 3466 patients received a PB during the study period. The ratio of PB to IIB dropped from 14% to 4% between 2003 and 2023. Primary, primary-assisted, and secondary patency rates were 65%, 76%, and 80%, respectively, and limb salvage rate was 83% at 1 year. Nineteen percent of centers performing IIBs in the VQI did not perform any PBs during the study period. Of the 246 centers performing PBs, 78% were LVC, 15% were MVC, and only 7% were HVC. On Cox regression analysis, HVCs were associated with a lower risk of primary patency loss (hazard ratio [HR], 0.79; 95% confidence interval [CI], 0.66-0.95; P = .010), reintervention (HR, 0.75; 95% CI, 0.60-0.95; P = .016), amputation (HR, 0.77; 95% CI, 0.61-0.98; P = .034), and MALE (HR, 0.78; 95% CI, 0.66-0.93; P = .005) compared with LVCs. No difference in secondary patency between high- and low-volume centers was observed (P = .680).

CONCLUSIONS

The utilization of PB operations experienced a four-fold decrease over the past 20 years, despite favorable patency and limb salvage outcomes. Centers with a higher operative volume in PB achieve better outcomes than LVCs, and accordingly, patients with extensive tibioperoneal disease may benefit from evaluation at centers with documented expertise in PB before resorting to an alternative revascularization modality or a major limb amputation.

The impact of angiographic pedal circulation status on wound healing in chronic limb-threatening ischemia after bypass surgery

OBJECTIVE

In the treatment of chronic limb-threatening ischemia (CLTI), complete wound healing is an important goal. Although foot perfusion status seems to be important for wound healing, the Global Limb Anatomic Staging System (GLASS) of the Global Vascular Guidelines does not include pedal artery status for the staging process due to the lack of sufficient evidence of its importance. This study aimed to clarify the importance of pedal perfusion status after bypass surgery.

METHODS

Among the 153 CLTI cases that underwent bypass distal to popliteal arteries from 2014 to 2018, 117 CLTI limbs with wounds and with sufficient pedal angiographic data were enrolled. They were classified into two groups, based on the wound status 6 months postoperatively; early wound healing group (EWG; n = 78), which achieved complete wound healing within 6 months postoperatively, and prolonged healing or unhealed wounds group (PWG; n = 39), which failed to achieve wound healing within 6 months. Various factors associated with wound healing, including the wound, ischemia, and foot infection (WIfI) classification, intraoperative graft flow, and pedal angiographic data, were analyzed. Regarding pedal angiographic data, in addition to the GLASS inframalleolar/pedal disease descriptor (IPD), newly formed classification system of the pedal circulation status in association with the location of wounds was included: pedal circulation status was classified into two groups as visualized arterial perfusion towards wounds (visualized perfusion) and non-visualized arterial perfusion towards wounds (non-visualized perfusion).

RESULTS

Univariate analysis showed preoperative albumin (Odds ratio [OR], 0.47; 95% confidence interval [CI], 0.24-0.94; P = .027), higher WIfI clinical stage (OR, 3.88; 95% CI, 1.74-10.1; P = .0005), higher IPD (OR, 2.16; 95% CI, 1.16-4.02; P = .012), and non-visualized perfusion to wounds (OR, 5.74: 95% CI, 2.45-14.0; P < .0001) as significant for prolonged wound healing. Multivariate analysis showed higher WIfI stage (OR, 5.04; 95% CI, 1.74-14.6; P = .0029) and non-visualized perfusion to wounds (OR, 4.34; 95% CI, 1.71-11.0; P = .0021) as significant, whereas IPD was not detected as significant. Regarding blood supply to the foot, although graft flow was significantly lower in IPD-P2 than IPD-P0/P1, graft flow was similar regardless of the status of angiographic circulation to wounds, suggesting that distribution of blood supply to the wound would be more important than total amount of blood supply to the foot for wound healing.

CONCLUSIONS

WIfI clinical stage and pedal circulatory environment were important factors for wound healing after bypass surgery. Pedal anatomical classification system including perfusion status would be important for decision making in CLTI treatment.

Primary Limb-Based Patency for Chronic Limb-Threatening Ischemia Treated with Endovascular Therapy Based on the Global Limb Anatomic Staging System

PURPOSE

To validate the correlation between the Global Limb Anatomic Staging System (GLASS) and primary limb-based patency (LBP) and to identify the risk factors associated with LBP loss.

MATERIALS AND METHODS

A single-center retrospective analysis was performed on patients with chronic limb-threatening ischemia (CLTI) who underwent endovascular therapy (EVT) between January 2018 and May 2022. All lesions were categorized into 3 groups (GLASS Stages I, II, and III). The primary LBP rates were analyzed and compared across the GLASS stages. The risk factors for the loss of primary LBP were identified using Cox regression analysis.

RESULTS

In total, 236 limbs from 231 patients were included, with 52 (22%) limbs stratified as GLASS Stage I, 59 (25%) limbs as GLASS Stage II, and 125 (53%) limbs as GLASS Stage III. The 1-year LBP rates for limbs classified as GLASS Stages I, II, and III were 78.8%, 69.5%, and 41.6%, respectively (P < .001). The long-term LBP rate was 54.2% in GLASS Stage I, 38.6% in GLASS Stage II, and 10.5% in GLASS Stage III (P < .001). Multivariate analysis revealed that GLASS stages (GLASS Stage Ⅰ vs Ⅲ, hazard ratio [HR], 0.36; 95% CI, 0.18-0.72; P = .004; GLASS Stage Ⅱ vs Ⅲ, HR, 0.47; 95% CI, 0.25-0.86; P = .02), diabetes, smoking, and sex were independently associated with LBP.

CONCLUSIONS

GLASS Stage III was associated with lower LBP rates in patients with CLTI who underwent EVT. The GLASS stages may serve as prognostic indicators for patients with CLTI after intervention.

Anatomical and clinical factors associated with infrapopliteal arterial bypass outcomes in patients with chronic limb-threatening ischemia

The aim of this study was to identify anatomical and clinical factors associated with limb-based patency (LBP) loss, major adverse limb events (MALEs), and poor amputation-free survival (AFS) after an infrapopliteal arterial bypass (IAB) surgery according to the Global Limb Anatomic Staging System. A retrospective analysis of patients undergoing IAB surgery between January 2010 and December 2021 at a single institution was performed. Two-year AFS, freedom from LBP loss, and freedom from MALEs were assessed using the Kaplan-Meier method. Anatomical and clinical predictors were assessed using multivariate analysis. The total number of risk factors was used to calculate risk scores for subsequent categorization into low-, moderate-, and high-risk groups. IABs were performed on 103 patients. The rates of two-year freedom from LBP loss, freedom from MALEs, and AFS were 71.3%, 76.1%, and 77.0%, respectively. The multivariate analysis showed that poor run-off beyond the ankle and a bypass vein caliber of < 3 mm were significantly associated with LBP loss and MALEs. Moreover, end-stage renal disease, non-ambulatory status, and a body mass index of < 18.5 were significantly associated with poor AFS. The rates of freedom from LBP loss and MALEs and the AFS rate were significantly lower in the high-risk group than in the other two groups (12-month low-risk rates: 92.2%, 94.8%, and 94.4%, respectively; 12-month moderate-risk rates: 58.6%, 84.6%, and 78.3%, respectively; 12-month high-risk rates: 11.1%, 17.6%, and 56.2%, respectively; p < 0.001, p < 0.001, and p < 0.001, respectively). IAB is associated with poor clinical outcomes in terms of LBP, MALEs, and AFS in high-risk patients. Risk stratification based on these predictors is useful for long-term prognosis.

Validity of the Global Vascular Guidelines in Predicting Outcomes Based on First-Time Revascularization Strategy

BACKGROUND

The Global Vascular Guidelines (GVG) recommend selecting an endovascular versus open-surgical approach to revascularization for chronic limb-threatening ischemia (CLTI), based on the Global Limb Anatomic Staging System (GLASS) and wound, ischemia, and foot infection (WIfI) classification systems. We assessed the utility of GVG-recommended strategies in predicting clinical outcomes.

METHODS

We conducted a single-center, retrospective review of first-time lower-extremity revascularizations within a comprehensive limb-preservation program from 2010 to 2018. Procedures were stratified by (1) treatment concordance with GVG-recommended strategy (concordant versus nonconcordant groups), (2) GLASS stages I-III, and (3) endovascular versus open strategies. The primary outcome was 5-year freedom from major adverse limb events (FF-MALE), defined as freedom from reintervention or major amputation, and secondary outcomes included 5-year overall survival, freedom from major amputation, freedom from reintervention, and immediate technical failure (ITF) during initial revascularization. Kaplan-Meier (KM) survival analysis and multivariate analysis with Cox proportional hazard models were performed on the primary and secondary outcomes.

RESULTS

Of 281 first-time revascularizations for CLTI, 251 (89.3%) were endovascular and 186 (66.2%) were in the concordant group, with a mean clinical follow-up of 3.02 ± 2.40 years. Within the concordant group alone, 167 (89.8%) of revascularizations were endovascular. The concordant group had a higher rate of chronic kidney disease (60.8% vs. 45.3%, P = 0.02), WIfI foot infection grade (0.81 ± 1.1 vs. 0.56 ± 0.80, P = 0.03), and WIfI stage (3.1 ± 0.79 vs. 2.8 ± 1.2, P < 0.01) compared to the non-concordant group. After both KM and multivariate analyses, there were no significant differences in 5-year FF-MALE or overall survival between concordant and non-concordant groups. There was higher freedom from major amputation in the non-concordant group on KM analysis (83.9% vs. 74.2%, P = 0.025), though this difference was non-significant on multivariate analysis (hazard ratio [HR]: 0.49, 95% confidence interval [CI]: 0.21-1.15, P = 0.10). The open group had lower MALE compared to the endovascular group (HR: 0.39, 95% CI: 0.17-0.91, P = 0.029) attributed to a lower reintervention rate in the open group (HR: 0.31, 95% CI: 0.11-0.87, P = 0.026). GLASS stage was not associated with significant differences in outcomes, but the severity of GLASS stage was associated with ITF (2.1% in stage 1, 6.4% in stage 2, and 11.7% in stage 3, P = 0.01).

CONCLUSIONS

In this study, CLTI treatment outcomes did not differ significantly based on whether treatment was received in concordance with GVG-recommended strategy. There was no difference in overall survival between the endovascular and open groups, though there was a higher reintervention rate in the endovascular group. The GVG guidelines are an important resource to help guide the management of CLTI patients. However, in this study, both concordance with GVG guidelines and GLASS staging were found to be indeterminate in differentiating outcomes between complex CLTI patients treated primarily with an endovascular-first approach. The revascularization approach for a CLTI patient is a nuanced decision that must take into account patient anatomy and clinical status, as well as physician skill and experience and institutional resources.

Revascularization prevents amputation among patients with diabetic foot during the COVID-19 era

OBJECTIVE

The COVID-19 pandemic has led to significant changes in healthcare systems that impact the management of chronic diseases such as diabetic foot (DF). We hypothesized that lack of access to healthcare would increase the severity of disease and lead to worse outcomes.

METHODS

The medical records of patients with DF were reviewed to determine demographic data and outcomes including wound healing, major amputation (MA), and death. Groups were divided into the pre-COVID-19 era (15 March 2019-15 March 2020) and the COVID-19 era (16 March 2020-16 March 2021); multivariable logistic analysis was performed to identify risk factors for MA.

RESULTS

261 patients with DF were included, 163 in the pre-COVID-19 era and 98 during the COVID-19 era. Patients in the COVID-19 presented with increased cardiovascular disease (19 vs 7%, p = 0.01), increased mean HbA1C (9.1 ± 2.1 vs 8.2 ± 2.1, p = 0.008) and higher WIFI-IV stage (78 vs 53%, p ≤ 0.0001). Patients with DF in the COVID-19 era were more likely to require MA (41 vs 21%, p ≤ 0.0001). Revascularization (OR = 0.12; 95% CI, 0.038-0.38) was a protective factor to reduce MA.

CONCLUSIONS

MA among DF patients increased two-fold during the COVID-19 era. Revascularization avoids MA in diabetic patients even during the COVID-19 pandemic, suggesting that revascularization should be performed when possible.

A systematic review and meta-analysis of GLASS staging system in the endovascular treatment of chronic limb-threatening ischemia

OBJECTIVE

The objective of this study was to evaluate the application of the Global Anatomic Staging System (GLASS) in the endovascular treatment of chronic limb-threatening ischemia (CLTI).

METHODS

We performed systematic research between June 2019 and February 2022, including articles investigating the relationship of GLASS classification with the outcomes of endovascular interventions in the treatment of CLTI. Data from the included studies were pooled and meta-analyzed. The primary endpoints were limb-based patency (LBP) at 1-year follow-up and immediate technical failure (ITF). Secondary endpoints included major amputation. We performed subgroup analysis between studies that reported on calcium modifier inclusion during GLASS classification and studies that did not.

RESULTS

Eleven studies, including 1816 patients (1975 limbs) met the inclusion criteria. The pooled ITF rates for GLASS stages I, II, and III are 5.52% (95% confidence interval [CI], 3.74%-8.07%), 7.39% (95% CI, 5.32%-10.18%), and 21.07% (95% CI, 13.48%-31.39%) respectively. The pooled LBP for GLASS stages I, II, and III are 68.43% (95% CI, 53.44%-80.37%), 41.52% (95% CI, 18.91%-68.37%), and 38.64% (95% CI, 19.83%-61.57%). The relative risk (RR) for ITF regarding composite GLASS I and II stages vs GLASS III is 3.96 (95% CI, 1.96-7.98). The RR for LBP of GLASS I and II versus GLASS stage III is 1.51 (95% CI, 0.86-2.64). Pooled major amputation rates for the composite GLASS I, II and GLASS III stages are 7.62% (95% CI, 5.44%-10.58%) and 15.43% (95% CI, 11.72%-20.05%) respectively, whereas the RR between GLASS I, II, and GLASS III stages is 1.84 (95% CI, 1.18-2.87).

CONCLUSIONS

Our study demonstrated that patients with CLTI undergoing endovascular interventions classified as GLASS stage III had almost a four-fold risk increase for ITF and 1.84 times the risk of major amputation compared with stages I and II. Additionally, GLASS classification correctly predicted ITF for all three stages, whereas it failed to predict stage I and II LBP outcomes. Safe conclusions regarding LBP cannot be drawn due to the low quality and small number of the included studies, necessitating further research. Furthermore, we displayed the importance of calcium moderator inclusion in the accurate classification of GLASS.

Global Limb Anatomic Staging System Inframalleolar Modifier Predicts Limb Salvage and Wound Healing in Patients with Chronic Limb Threatening Ischaemia Undergoing Endovascular Infrainguinal Revascularisation

OBJECTIVE

This study aimed to analyse the influence of the Global Anatomic Staging System (GLASS) and inframalleolar (IM) disease on the treatment outcomes of patients with chronic limb threatening ischaemia (CLTI) who undergo endovascular treatment (EVT) METHODS: Data of patients who underwent infrainguinal endovascular therapy (EVT) for CLTI between 2015 and 2019 at two centres were analysed retrospectively. The endpoints were major amputation, major adverse limb events (MALE), and wound healing.

RESULTS

Overall, 276 patients and 340 limbs were analysed. The number of revascularisations for an infrapopliteal lesion was 48 (70.6%), 63 (63.0%), and 142 (82.6%) in the GLASS I, GLASS II, and GLASS III stages, respectively (p < .001). There was no statistically significant difference in limb salvage among the GLASS stages (p = .78). The limb salvage rates at one year were 94.6%, 88.0%, and 70.0% in the IM P0 P1, and P2 groups, respectively (p < .001). Multivariable analysis showed that Wound, Ischemia, and foot Infection (WIfI) stage, and IM grade were risk factors for major amputation. The freedom from MALE rates at two years were 60.5%, 45.3%, and 41.1% in the GLASS I, II, and III stages, respectively (p = .003) and 64.1%, 43.5%, and 18.4% in the IM P0, P1, and P2 groups, respectively (p < .001). Multivariable analysis demonstrated that WIfI stage, GLASS stage, IM grade, and infrapopliteal revascularisation were risk factors for MALE. There was no significant difference in wound healing among GLASS I - III (p = .75). The wound healing rates at 365 days were 78.6%, 68.6%, and 42.0% in the IM P0, P1, and P2 groups, respectively (p = .065). Multivariable analysis showed that WIfI stage and IM P2 were risk factors for incomplete wound healing.

CONCLUSION

GLASS IM was associated with major amputation, MALE, and wound healing, while GLASS stage was associated with only MALE.

Role of the Global Limb Anatomic Staging System in predicting outcomes of chronic limb-threatening ischemia in patients treated by drug-coated balloons

Background

The Global Limb Anatomic Staging System (GLASS) was proposed to assess the procedural complexity and technical failure rate and stratify the anatomic pattern of chronic limb-threatening ischemia (CLTI). However, more evidence is needed to validate the GLASS in staging outcomes after endovascular therapy in patients with CLTI treated with drug-coated balloons (DCBs). This study aims to evaluate the role of the GLASS in predicting outcomes of CLTI patients treated with DCBs.

Methods

This multicenter, retrospective cohort study enrolled patients with CLTI treated with DCBs from July 2016 to June 2019. GLASS stages were assigned for every limb. The limb-based patency (LBP) rate, clinically driven target lesion revascularization (CD-TLR) rate, clinical improvement, and safety endpoints were analyzed and compared across the GLASS stages over 12 months of follow-up. Risk factors for the loss of LBP were identified using Cox regression analysis.

Results

A total of 90 limbs were enrolled, with 55 (61.1%) having isolated femoropopliteal lesions and 35 (38.9%) having femoropopliteal and infrapopliteal lesions. Of the limbs, 17 (18.9%), 12 (13.3%), and 61 (67.8%) were assigned to GLASS stages I, II, and III, respectively. The Kaplan-Meier estimate of the 12-month LBP was 65.4%, and no difference was found among the different stages (stage I 81.1%; stage II 85.2%; stage III 54.4%; P=0.080). The LBP was lower in stage III than in stages I and II combined (stage I and II 83.5%; stage III 54.4%; P=0.027). Similar results were found for the freedom from CD-TLR rates among the different stages. The ankle-brachial index values improved from 0.42±0.29 to 0.78±0.35 at follow-up (P<0.001). The rates of mortality, any amputation, and major amputation were similar among the groups. GLASS stage III and coronary heart disease were identified as independent risk factors for the loss of LBP at 12 months.

Conclusions

The 1-year LBP and freedom from CD-TLR rates were lower in GLASS stage III than in stages I and II. The GLASS classification could predict the outcomes of CLTI patients with femoropopliteal lesions treated with DCB.

Multidisciplinary approach to decreasing major amputation, improving outcomes, and mitigating disparities in diabetic foot and vascular disease

Major nontraumatic lower extremity amputation (LEA) is a morbid complication of longstanding or poorly controlled diabetes and/or end-stage peripheral artery disease. Incidence of major LEAs consistently declined during the 1990s and 2000s, but rates have plateaued or increased in many regions during the past decade. Marked racial, ethnic, socioeconomic, and geographic disparities in risk of LEA persist and are related to inequalities in access to care and differential rates of attempted limb preservation. Multidisciplinary diabetic foot care (MDFC) is increasingly recognized as a necessary model for optimal management of patients with diabetic foot and vascular disease. This article reviews the role of MDFC in reducing major LEAs and the specific ways in which MDFC can mitigate disparities in care delivery and limb preservation outcomes. Access to MDFC among vulnerable populations remains a significant barrier to systematic reduction in major LEAs.

Aortic calcification index predicts mortality and cardiovascular events in operatively treated patients with peripheral artery disease A prospective PUREASO cohort follow-up study

OBJECTIVE

Present study evaluates the association of aortic calcification to mortality and major adverse cardiovascular and leg events (MACE and MALE) in patients with peripheral artery disease (PAD). The risk for mortality and MACE and MALE events is considered in clinical decision making.

METHODS

This cohort found in 2012 - 2013 consists of 226 symptomatic PAD patients referred to Turku University Hospital for invasive treatment. Follow-up data about mortality and survival without MACEs and MALEs was collected up to 5 years from inclusion date and aortic calcification index (ACI) was measured from patients with available imaging studies (164 of 226). ACIs association with events and mortality was evaluated in Cox regression, Kaplan-Meier and Classification and regression tree analysis.

RESULTS

All-cause mortality at 1, 3 and 5 years was 13.7%, (31), 26.1% (59) and 46.9% (106), respectively. In multivariable Cox regression analysis ACI and ACI>43 were independent risk factors for all-cause mortality (HR 1.13 per 10 units 95%CI, 1.00-1.22 and HR 1.83, 95%CI, 1.01-3.32, respectively) and for MACE (HR 1.10 per 10 units, 95%CI, 1.00-1.22 and HR 3.14, 95%CI, 1.67-5.91, respectively), but not for MALES. Classification and regression tree analysis showed that ACI 43 best divides cohort in relation to mortality. Kaplan-Meier analyses showed that ACI>43 is associated with greater mortality and occurrence of MACEs compared to those who have ACI≤43 (log-rank p-value 0.005 and 0.0012, respectively).

CONCLUSION

Risk for mortality and MACEs is associated with high ACI. ACI can expose PAD patients' risk for further cardiovascular events and mortality.

Limb-based patency as a measure of effective revascularization for chronic limb-threatening ischemia

OBJECTIVE

In 2019, the Global Vascular Guidelines on chronic limb-threatening ischemia (CLTI) introduced the concept of limb-based patency (LBP) defined as maintained patency of a target artery pathway (TAP) following intervention. The purpose of this study was to investigate the relationship between LBP and major adverse limb events following infrainguinal revascularization for CLTI.

METHODS

Consecutive patients undergoing revascularization for CLTI between 2016 and 2019 at a single tertiary institution with a dedicated limb preservation team were included. Subjects with aorto-iliac disease, prior infrainguinal stents or existing bypass grafts were excluded. Demographics, Global Limb Anatomic Staging System (GLASS) scores, Wound, Ischemia, foot Infection (WIfI) stages, revascularization details, and limb-specific outcomes were reviewed. LBP was defined by the absence of re-intervention, occlusion, critical stenosis (>70%), or hemodynamic compromise with ongoing symptoms of CLTI. Major adverse limb events (MALE) included thrombectomy or thrombolysis, new bypass, open surgical graft revision and/or major amputation.

RESULTS

184 unique limbs in 163 patients were analyzed. This cohort was composed of 66.9% male patients with a mean age of 72. Baseline characteristics included diabetes (66%), tissue loss (91%) and advanced WIfI stages (30% stage 3, 51% stage 4). GLASS stage 3 anatomic patterns were common (n=119; 65%). 60 limbs were treated with open bypass (65% involving tibial targets) while 124 underwent endovascular intervention (70% including infrapopliteal targets). 12-month freedom from MALE and loss of LBP were 74.0%±3.7% and 48.6%±4.2%, respectively. Diabetes (HR=2.56 [1.13-5.83]; p=.025) and loss of LBP (4.12 [1.96-8.64]; p<.001) were independent predictors of MALE in a Cox proportional hazard model. Loss of LBP was the sole independent predictor of major limb amputation after revascularization (HR=4.97 [1.89-13.09]; p=.001). Loss of LBP impacted both intermediate-risk limbs (HR=2.85 [1.02-7.97]; p=.047 in WIfI stages 1-3) and high-risk limbs (HR=3.99 [1.32-12.11]; p=.014 in WIfI stage 4). However, loss of LBP had the greatest impact on patients presenting with WIfI stage 4 disease (31% vs. 8% major limb amputation at 12-months in limbs without vs. with maintained LBP).

CONCLUSIONS

Anatomic durability of revascularization, as measured by LBP, is a key determinant of treatment outcomes in CLTI regardless of the initial mode of intervention undertaken. Loss of LBP is most detrimental in patients presenting with advanced limb threat (WIfI stage 4).

Patient-centered clinical success after lower extremity revascularization for complex diabetic foot wounds treated in a multidisciplinary setting

OBJECTIVE

Physician-oriented outcomes, such as patency and amputation-free survival (AFS), have traditionally been markers of success after lower extremity revascularization. Previous studies have defined clinical success based on a composite of patient-centered outcomes and have shown this outcome to be achieved in less than 50% of patients, far lower than standard physician-oriented outcomes. The purpose of this study is to evaluate clinical success after lower extremity bypass (LEB) or peripheral vascular intervention (PVI) for tissue loss in diabetic patients treated in a multidisciplinary setting to better understand what factors are associated with success from a patient's perspective.

METHODS

All patients presenting to our multidisciplinary diabetic limb preservation service from July 2012 to January 2020 were enrolled in a prospective database. Patients who underwent either LEB or PVI for ulcer or gangrene were included in the analysis. Clinical success was defined as the composite outcome of secondary patency to the point of wound healing, limb salvage for 1 year, maintenance of ambulatory status for 1 year, and survival for 6 months. Secondary outcomes included 1-year wound healing, patency, and AFS.

RESULTS

A total of 134 revascularizations were performed in 131 patients, including 91 (68%) PVI and 43 (32%) LEB. Patients were more frequently male (64%) and black (61%), and 16% were dialysis-dependent. All patients had tissue loss (53% ulcer, 47% gangrene). There were 5 (3.7%) wound, ischemia, and foot infection stage 1, 6 (6.0%) stage 2, 29 (22%) stage 3, and 92 (69%) stage 4 limbs at the time of revascularization. Overall, 76.9% of patients preserved secondary patency to the point of wound healing, 92.5% had limb salvage for 1 year, 90.3% had maintenance of ambulatory status for 1 year, and 96.3% survived for 6 months. The clinical success composite outcome was achieved in 71.6% of patients and was not statistically different between those undergoing PVI vs LEB (69.2% vs 76.7%, P = .37). Secondary patency, limb salvage, and AFS at 1 year were 80.8% ± 3.6%, 91.8% ± 2.3%, and 83.3% ± 3.1%, respectively. Wound healing at 1 year was 84.3% ± 3.4%. The only covariate associated with clinical failure on multivariable analysis was increased age (odds ratio, 0.95; 95% confidence interval, 0.91-0.99; P = .008).

CONCLUSIONS

Among diabetic patients presenting with tissue loss, the composite outcome of patient-centered clinical success is lower than traditional physician-centered outcomes after lower extremity revascularization, mostly due to low rates of secondary patency to the point of wound healing. In the current study, clinical failure was only associated with older age and was no different after PVI compared with LEB.